The Trump administration's bid to limit which wetlands and streams are covered by the Clean Water Act is backed by an analysis that assumes many states will boost regulations as federal oversight retreats. But state regulators and environmental experts say closing that gap will be all but impossible.

The Trump administration's bid to limit which wetlands and streams are covered by the Clean Water Act is backed by an analysis that assumes many states will boost regulations as federal oversight retreats. But state regulators and environmental experts say closing that gap will be all but impossible.